Cup wash disk with shims

ABSTRACT

A cup wash disk for cleaning a photoresist process tool is provided. An upper plate is arranged over a lower plate to define a cavity between the upper and lower plates. The lower plate comprises peripheral openings in fluid communication with the cavity and arranged along a periphery of the lower plate. A plurality of shims is arranged between the upper and lower plates to space the upper and lower plates and to define slits between the upper and lower plates. The slits are in fluid communication with the cavity. A method for cleaning the photoresist process tool using the cup wash disk is also provided.

REFERENCE TO RELATED APPLICATION

This Application is a Continuation of U.S. application Ser. No.16/360,354, filed on Mar. 21, 2019, which is a Divisional of U.S.application Ser. No. 14/995,305, filed on Jan. 14, 2016 (now U.S. Pat.No. 10,265,735, issued on Apr. 23, 2019). The contents of theabove-referenced patent applications are hereby incorporated byreference in their entirety.

BACKGROUND

During the manufacture of integrated circuits (ICs), multi-stepsequences of semiconductor manufacturing processes are performed togradually form electronic circuits on semiconductor substrates. One suchsemiconductor manufacturing process is photolithography.Photolithography is a process for transferring a geometric pattern froma photomask to a photoresist layer using radiation. The process includesdepositing the photoresist layer, exposing the photoresist layer toradiation that passes through and is patterned by the photomask, anddeveloping the photoresist layer.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a perspective view of some embodiments of a cup washdisk (CWD) with shims.

FIG. 2A illustrates a top view of some embodiments of the CWD of FIG. 1.

FIGS. 2B and 2C illustrate various cross-sectional views of someembodiments of the CWD of FIG. 2A.

FIG. 3A illustrates a perspective view of more detailed embodiments ofthe CWD of FIG. 1.

FIG. 3B illustrates a top view of some embodiments of the CWD of FIG.3A.

FIG. 4 illustrates a cross-sectional view of some embodiments of the CWDof FIG. 1 arranged in a photoresist process tool.

FIGS. 5-8 illustrate a series of cross-sectional views of someembodiments of a method for using a photoresist process tool, andsubsequently cleaning the photoresist process tool with a CWD comprisingshims.

FIG. 9 illustrates a flowchart of some embodiments of a method for usinga photoresist process tool, and subsequently cleaning the photoresistprocess tool with a CWD comprising shims.

DETAILED DESCRIPTION

The present disclosure provides many different embodiments, or examples,for implementing different features of this disclosure. Specificexamples of components and arrangements are described below to simplifythe present disclosure. These are, of course, merely examples and arenot intended to be limiting. For example, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed between the first and second features, such thatthe first and second features may not be in direct contact. In addition,the present disclosure may repeat reference numerals and/or letters inthe various examples. This repetition is for the purpose of simplicityand clarity and does not in itself dictate a relationship between thevarious embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Some processes for the deposition of a photoresist layer involve theapplication of a liquid photoresist material to a surface of a spinningworkpiece. While the spinning promotes a uniform application of theliquid photoresist material, the spinning may also result in thesplashing and/or spraying of the liquid photoresist material and thebuildup of the liquid photoresist material on surfaces of a processchamber accommodating the spinning workpiece. The buildup may, in turn,lead to contamination of other workpieces placed in the process chamber.One solution is to clean the process chamber between uses.

To clean the process chamber, a cup wash disk (CWD) is placed within theprocess chamber. The CWD may comprise an upper plate arranged over andabutting a lower plate to define a cavity between the upper and lowerplates. The lower plate comprises a lower opening on a bottom of thelower plate and a plurality of peripheral openings arranged along aperiphery of the lower plate. The lower opening and the peripheralopenings are in fluid communication with the cavity, and the loweropening is configured to receive a solvent. After placing the CWD withinthe process chamber, the CWD is spun while a solvent is sprayed into thelower opening from under the CWD. Due to centrifugal force, the solventtravels within the cavity to the peripheral openings, and splashesand/or sprays onto surfaces of the process chamber. The solvent thendissolves the buildup and cleans the process chamber.

While the CWD facilitates cleaning of the process chamber, the CWD mayfail to effectively clean an outer sidewall (or cup) of the processchamber for certain designs of the process chamber. For example, theprocess chamber may comprise an inner sidewall (or cup) obstructing thelateral spray of solvent to the outer sidewall. Where the CWD fails toeffectively clean the outer sidewall, the time it takes to clean theprocess chamber and/or the amount of solvent used to clean the processchamber may increase, thereby increasing costs.

The present application is directed to a CWD with shims arranged betweenupper and lower plates that define a cavity. The lower plate comprisesperipheral openings arranged along a periphery of the lower plate and influid communication with the cavity. Further, the lower plate comprisesa lower opening in fluid communication with the cavity. The shims spacethe lower and upper plates, and define a plurality of slits between thelower and upper plates. The slits are arranged over the peripheralopenings, along a periphery of the upper and lower plates, and are influid communication with the cavity. Advantageously, the slits increasea height of a lateral spray of solvent from the CWD during use of theCWD. Such increased height may allow the lateral spray to reach an outersidewall of a process chamber unimpeded by an inner sidewall of theprocess chamber. As such, the CWD may be effective at cleaning the outersidewall, thereby saving solvent, money, and time during cleaning.

With reference to FIG. 1, a perspective view 100 of some embodiments ofa CWD 102 with shims 104 a, 104 b is provided. As illustrated, the shims104 a, 104 b are arranged between an upper plate 106 and a lower plate108 to define slits 110 a, 110 b, 110 c between the upper and lowerplates 106, 108. The shims 104 a, 104 b are confined to a periphery ofthe upper and lower plates 106, 108 and, in some embodiments, are evenlyspaced around the periphery of the upper and lower plates 106, 108.Further, in some embodiments, the shims 104 a, 104 b directly abut theupper and lower plates 106, 108. The shims 104 a, 104 b may be, forexample, Teflon (e.g., polytetrafluoroethylene), and/or the shims 104 a,104 b and the slits 110 a, 110 b, 110 c may have a thickness T of about0.1 millimeters.

The upper and lower plates 106, 108 define a cavity (not shown)therebetween that is in fluid communication with the slits 110 a, 110 b,110 c. The cavity comprises a recess (not shown) in a lower surface ofthe upper plate 106 and/or a recess (not shown) in an upper surface ofthe lower plate 108. The upper and/or lower plates 106, 108 compriseperipheral openings 114 a, 114 b, 114 c, 114 d in fluid communicationwith the cavity and arranged along a periphery of the upper and/or lowerplates 106, 108. In some embodiments, the peripheral openings 114 a, 114b, 114 c, 114 d are evenly spaced laterally around the periphery of theupper and/or lower plates 106, 108, and/or restricted to the lower plate108. Further, the lower plate 108 comprises a lower opening (not shown)in fluid communication with the cavity. In some embodiments, the upperand lower plates 106, 108 share a circular footprint and/or sidewallsurfaces of the upper and lower plates 106, 108 are coplanar.

In use, the CWD 102 is placed on a workpiece support within a chamber ofa photoresist process tool that is configured to deposit photoresist.The CWD 102 is then rotated through the workpiece support while a streamof solvent is sprayed into the cavity through the lower opening.Centrifugal force moves or accelerates the solvent to the periphery ofthe CWD 102 where it sprays out the slits 110 a, 110 b, 110 c and theperipheral openings 114 a, 114 b, 114 c, 114 d to surfaces of thechamber. Upon interfacing with the surfaces, the solvent dissolves anybuildup of photoresist on the surfaces, thereby cleaning the chamber.Advantageously, the slits 110 a, 110 b, 110 c may be elevated relativeto the peripheral openings 114 a, 114 b, 114 c, 114 d, such that theslits 110 a, 110 b, 110 c may provide effective cleaning of surfacesthat cannot be reached by solvent spraying out of the peripheralopenings 114 a, 114 b, 114 c, 114 d. This advantageously allowsefficient use of solvent, low cost, and quick cleaning.

With reference to FIG. 2A, a top view 200A of some embodiments of theCWD 102 of FIG. 1 is provided. As illustrated, a plurality of shims 104a, 104 b, 104 c, 104 d (shown in phantom) are arranged under an upperplate 106 and laterally spaced around a periphery of the upper plate106. For example, the shims 104 a, 104 b, 104 c, 104 d may comprise fourshims laterally spaced evenly around a periphery of the upper plate 106.

With reference to FIG. 2B, a cross-sectional view 200B of someembodiments of the CWD 102 of FIG. 2A is provided. The cross-sectionalview 200B is taken along line A-A′ in FIG. 2A. As illustrated, a cavity202 is arranged between upper and lower plates 106, 108 and comprises arecess in the lower plate 108 and/or the upper plate 106. In someembodiments, the cavity 202 is ring shaped.

The upper and/or lower plates 106, 108 comprise peripheral openings 114d, 114 e, 114 f (only some of which are labeled) in fluid communicationwith the cavity 202 and arranged along a periphery of the upper and/orlower plates 106, 108. The peripheral openings 114 d, 114 e, 114 f maybe, for example, horizontal, vertical, or angled upward or downward. Insome embodiments, the peripheral openings 114 d, 114 e, 114 f comprise avertical peripheral opening 114 f extending vertically to the cavity 202through a bottom surface 204 of the lower plate 108. In someembodiments, the peripheral openings 114 d, 114 e, 114 f comprise ahorizontal peripheral opening 114 d extending laterally to the cavity202 through an outer sidewall surface 206 of the lower plate 108. Insome embodiments, in some embodiments, the peripheral openings 114 d,114 e, 114 f comprise an angled peripheral opening 114 e extendingupward at about 45 degrees to horizontal, through a lower corner of thelower plate 108, to the cavity 202. Further, the lower plate 108comprises a lower (or bottom) opening 208 in fluid communication withthe cavity 202 and configured to receive solvent (shown by arrows). Insome embodiments, the lower opening 208 is ring shaped, and/or laterallyspaced between a central axis 210 of the CWD 102 and the peripheralopenings 114 d, 114 e, 114 f. Further, in some embodiments, the loweropening 118 is arranged on the bottom surface 204 of the lower plate108.

A plurality of shims 104 b, 104 d are arranged between the upper andlower plates 106, 108 to space the upper plate 106 from the lower plate108. The shims 104 b, 104 d are laterally spaced along the periphery ofthe upper plate 106 to define slits (not shown) between the upper andlower plates 106, 108. In some embodiments, outer sidewall surfaces 212of the shims 104 b, 104 d (only one of which is labeled) are coplanarwith the outer sidewall surface 206 of the lower plate 108 and/or anouter sidewall surface 214 of the upper plate 106. The slits are influid communication with the cavity 202 and provide an outlet forsolvent entering the cavity 202. In some embodiments, the shims 104 b,104 d have a thickness T of about 0.1 millimeters.

With reference to FIG. 2C, another cross-sectional view 200C of someembodiments of the CWD 102 of FIG. 2A is provided. The cross-sectionalview 200C is taken along line B-B′ in FIG. 2A. As illustrated, aplurality of peripheral openings 114 g, 114 h, 114 i (only some of whichare labeled) are arranged along a periphery of a lower plate 108 influid communication with a cavity 202 between the lower plate 108 and anupper plate 106. Further, shims (not shown) are arranged between theupper and lower plates 106, 108 to define slits 110 c (only one of whichis labeled). The slits 110 c are in fluid communication with the cavity202 and are arranged along a periphery of the upper and lower plates106, 108, vertically between the upper and lower plates 106, 108 andlaterally between the shims. In some embodiments, the slits 110 c arearranged over the peripheral openings 114 g, 114 h, 114 i. For example,the slits 110 c may be spaced over the peripheral openings 114 g, 114 h,114 i by a distance D of about 3 millimeters. Further, in someembodiments, the slits 110 c are arranged in direct fluid communicationwith the cavity 202. The slits 110 c and the peripheral openings 114 g,114 h, 114 i provide outlets for solvent (shown by arrows) entering thecavity 202.

With reference to FIG. 3A, a perspective view 300A of more detailedembodiments of the CWD 102 of FIG. 1 is provided. As illustrated, a shimstructure 302 is arranged on an upper plate 106 to space the upper plate106 from a lower plate 108. In some embodiments, the shim structure 302is Teflon (e.g., polytetrafluoroethylene) or some other polymer, and/oris molded. The shim structure 302 comprises a ring-shaped region 304, aplurality of shims 104 b, and a plurality of flexible members 306 a. Forease of illustration, only one of the shims 104 a and one of theflexible members 306 a are labeled.

The ring-shaped region 304 is arranged over the upper plate 106. In someembodiments, the ring-shaped region 304 is arranged directly on theupper plate 106, and/or has an outer diameter exceeding that of theupper plate 106. The shims 104 b are arranged between the upper andlower plates 106, 108 to define slits 110 b between the upper and lowerplates 106, 108. For ease of illustration, only one of the slits 110 bis labeled. The shims 104 b are confined to a periphery of the upper andlower plates 106, 108 and, in some embodiments, are laterally spacedevenly around the periphery of the upper and lower plates 106, 108. Theflexible members 306 a extend between outer edges of the shims 104 b andthe ring-shaped region 304, along an outer sidewall surface 214 of theupper plate 106, to connect the shims 104 b to the ring-shaped region304. In some embodiments, a length of the flexible members 306 a isabout equal to a thickness of the upper plate 106, and/or the flexiblemembers 306 a directly abut the outer sidewall surface 214 of the upperplate 106. The flexible members 306 a are flexible to deflect away fromsidewall surface 214 so as to add the shim structure 302 to the upperplate 106, or to remove the shim structure 302 from the upper plate 106.

With reference to FIG. 3B, a top view 300B of some embodiments of theCWD 102 of FIG. 3A is provided. As illustrated, a ring-shaped region 304of a shim structure 302 partially covers an upper plate 106. Further, aplurality of shims 104 a, 104 b, 104 c, 104 d (shown in phantom) arearranged under the upper plate 106 and laterally spaced around aperiphery of the ring-shaped region 304. For example, the shims 104 a,104 b, 104 c, 104 d may comprise four shims laterally spaced evenlyaround a periphery of the ring-shaped region 304. The shims 104 a, 104b, 104 c, 104 d are connected to the ring-shaped region 304 byrespective flexible members 306 a, 306 b, 306 c, 306 d (also shown inphantom) that are laterally spaced around the periphery of thering-shaped region 304 with the shims 104 a, 104 b, 104 c, 104 d.

With reference to FIG. 4, a cross-sectional view 400 of some embodimentsof the CWD 102 of FIG. 1 arranged in a photoresist process tool 402 isprovided. The photoresist process tool 402 is configured to depositphotoresist, such as liquid photoresist, on workpieces (not shown), andthe CWD 102 is configured to spray solvent to clean the photoresistprocess tool 402 of excess photoresist between depositions.

As illustrated, the CWD 102 is arranged in a housing 404 of thephotoresist process tool 402 and comprises a cavity 202 arranged betweenupper and lower plates 106, 108. The upper and/or lower plates 106, 108comprise peripheral openings 114 d, 114 j in fluid communication withthe cavity 202 and arranged along a periphery of the upper and/or lowerplates 106, 108. Further, the lower plate 108 comprises a lower (orbottom) opening 208 in fluid communication with the cavity 202. Shims(not shown) are arranged between the upper and lower plates 106, 108 todefine slits 110 a, 110 c along a periphery of the CWD 102, laterallybetween the shims and vertically between the upper and lower plates 106,108.

A chamber 406 of the housing 404 accommodates a workpiece support 408and back rinse nozzles 410 a, 410 b. The workpiece support 408 comprisesan upper side configured to support the CWD 102 or a workpiece (notshown), and further comprises a lower side mechanically coupled to amotor 412 through a shaft 414. The motor 412 is configured to rotate theworkpiece support 408 through the shaft 414. The back rinse nozzles 410a, 410 b are configured to spray a solvent into the lower opening 208 ofthe CWD 102. The chamber 406 is partially defined by an inner sidewall(or cup) 416 and an outer sidewall (or cup) 418 laterally surroundingthe workpiece support 408. The inner sidewall 416 protrudes to a firstheight above the workpiece support 408, and the outer sidewall 418protrudes to a second height above the workpiece support 408 that isgreater than the first height. Further, the outer sidewall 418 laterallysurrounds and is laterally spaced from the inner sidewall 416.

An exhaust channel 420 of the housing 404 is configured to remove excessphotoresist and/or solvent from the chamber 406. In some embodiments,the exhaust channel 420 is arranged under and along a periphery of thechamber 406, and/or laterally surrounds the chamber 406. The exhaustchannel 420 extends from an inlet 422 abutting the chamber 406 to one ormore outlets 424, 426 underlying the inlet 422. The inlet 422 isarranged on an upper side of the housing 404 between the inner and outersidewalls 416, 418. Further, in some embodiments, the inlet 422laterally surrounds the chamber 406 along a periphery of the housing 404(e.g., is ring shaped). The outlet(s) 424, 426 comprise a photoresistoutlet 424 for excess photoresist and/or a solvent outlet 426 for excesssolvent. In some embodiments, the photoresist outlet 424 is arranged ona lower side of the housing 404 and/or laterally encloses the chamber406 along a periphery of the housing 404 (e.g., is ring shaped).Further, in some embodiments, the solvent outlet 426 is arrangeddirectly under the chamber 406, downstream from the photoresist outlet424. To prevent photoresist from moving along the exhaust channel 420from the photoresist outlet 424 to the solvent outlet 426, the exhaustchannel 420 may move up and then down between the photoresist andsolvent outlets 424, 426. Due to the increased density of photoresistrelative to solvent, the photoresist is unable to move upward with thesolvent.

During cleaning of the photoresist process tool 402, the back rinsenozzles 410 a, 410 b spray solvent into the lower opening 208 of the CWD102 while the CWD 102 is rotated by the motor 412. Centrifugal forcemoves or accelerates the solvent to a periphery of the CWD 102 where itsprays out of the peripheral openings 114 d, 114 j of the CWD 102 andthe slits 110 a, 110 c of the CWD 102. Advantageously, the slits 110 a,110 c may allow the outer sidewall 418 to be effectively cleaned. Forexample, where solvent spraying out of the peripheral openings 114 d,114 j towards the outer sidewall 418 is obstructed by the inner sidewall416, solvent spraying out of the slits 110 a, 110 c towards the outersidewall 418 may reach the outer sidewall 418 unimpeded by the innersidewall 416 since the slits 110 a, 110 c may be arranged over theperipheral openings 114 d, 114 j and a topmost point of the innersidewall 416. By effectively cleaning the outer sidewall 418, solvent,time, and money are saved.

With reference to FIGS. 5-8, a series of cross-sectional views of someembodiments of a method for using a photoresist process tool, andsubsequently cleaning the photoresist process tool with a CWD comprisingshims, is provided.

As illustrated by the cross-sectional view 500 of FIG. 5, a workpiece502 is placed in a chamber 406 of a photoresist process tool 402 on aworkpiece support 408 of the photoresist process tool 402. The workpiece502 may be, for example, a semiconductor wafer or substrate with or withone or more layers and/or devices arranged thereon. The semiconductorwafer or substrate may be, for example, a bulk semiconductor substrate,such as a bulk silicon substrate, or a silicon-on-insulator (SOI)substrate.

As illustrated by the cross-sectional view 600 of FIG. 6, a photoresistnozzle 602 is arranged over the workpiece 502 and the workpiece 502 isrotated by a motor 412 through the workpiece support 408. With theworkpiece 502 rotating, the photoresist nozzle 602 applies photoresist604 to the workpiece 502 to form a photoresist layer 606 on theworkpiece 502. In some embodiments, the photoresist nozzle 602 appliesthe photoresist 604 to the center of the workpiece 502, and/or thephotoresist 604 is applied in liquid form. Due to centrifugal force, theapplied photoresist 604 distributes evenly across the workpiece 502,thereby forming the photoresist layer 606 with a substantially uniformthickness. Further, excess photoresist 608 splashes and/or sprays offthe workpiece 502. Some of the excess photoresist 608 moves to an inlet422 of an exhaust channel 420 around a periphery of the chamber 406, andis subsequently removed from the photoresist process tool 402. Further,some of the excess photoresist 608 builds up on inner and outersidewalls 416, 418 partially defining the chamber 406 to form excessphotoresist layers 610, 612 on the inner and outer sidewalls 416, 418.

As illustrated by the cross-sectional view 700 of FIG. 7, the workpiece502 (see, for example, FIG. 6) is replaced with a CWD 102. In otherwords, the photoresist nozzle 602 (see, for example, FIG. 6) is removedfrom over the chamber 406 and the workpiece 502 is removed from thechamber 406. Further, the CWD 102 is placed in the chamber 406 on theworkpiece support 408. The CWD 102 comprises an upper plate 106 and alower plate 108 arranged under the upper plate 106. The upper and lowerplates 106, 108 are spaced from one another by shims (not shown)arranged therebetween to define slits 110 a, 110 c laterally spacedalong a periphery of the upper and/or lower plates 106, 108.

As illustrated by the cross-sectional view 800, the CWD 102 is rotatedby the motor 412 while back rinse nozzles 410 a, 410 b spray solvent 802(shown as arrows) into a cavity 202 of the CWD 102 through a lower (orbottom) opening 208 of the CWD 102. Due to centrifugal force, thesolvent 802 moves and/or accelerates through the cavity 202 toperipheral openings 114 d, 114 j of the CWD 102 and the slits 110 a, 110c, and concurrently sprays out the peripheral openings 114 d, 114 j andthe slits 110 towards the inner and outer sidewalls 416, 418. Uponinterfacing with the inner and outer sidewalls 416, 418, the solvent 802dissolves the excess photoresist layers 610, 612 that built up on theinner and outer sidewalls 416, 418 during photoresist deposition.Dissolved photoresist 804 and excess solvent 806 move to the inlet 422of the exhaust channel 420 and respectively travel to a photoresistoutlet 424 and a solvent outlet 426 for removal from the photoresistprocess tool 402.

In some embodiments, the back rinse nozzles 410 a, 410 b continuespraying the solvent 802 until the excess photoresist layers 610, 612are completely removed and/or until a predetermined period of time haselapsed. Further, in some embodiments, solvent spraying out of theperipheral openings 114 d, 114 j towards the outer sidewall 418 isobstructed by the inner sidewall 416, whereas solvent spraying out ofthe slits 110 a, 110 c passes to the outer sidewall 418 unobstructed bythe inner sidewall 416 since the slits 110 a, 110 c are arranged abovethe peripheral openings 114 d, 114 j and a topmost point of the innersidewall 416. In such embodiments, the CWD 102 advantageously allowsefficient cleaning of the chamber 406, which reduces solvent usage,time, and costs.

With reference to FIG. 9, a flowchart 900 of some embodiments of amethod for using a photoresist process tool, and subsequently cleaningthe photoresist process tool with a CWD comprising shims, is provided.

At 902, a workpiece is placed in a chamber of a photoresist processtool. The chamber is partially defined by an inner sidewall and an outersidewall extending to a location over the inner sidewall. See, forexample, FIG. 5.

At 904, photoresist is deposited on the workpiece while the workpiece isrotated, such that excess photoresist splashes and builds up on theinner and outer sidewalls. See, for example, FIG. 6.

At 906, the workpiece is replaced with a CWD. The CWD comprises shimsspacing upper and lower plates of the CWD to form slits. Further, thelower plate comprises peripheral openings. See, for example, FIG. 7.

At 908, a solvent is sprayed into a cavity of the CWD while the CWD isrotating, such that the solvent sprays out of the slits and theperipheral openings to clean a buildup of photoresist on the inner andouter sidewalls. The inner sidewall obstructs a spray of solvent out ofthe peripheral openings from reaching the outer sidewall but does notobstruct a spray of solvent out the slits from reaching the outersidewall. See, for example, FIG. 8.

While the method described by the flowchart 900 is illustrated anddescribed herein as a series of acts or events, it will be appreciatedthat the illustrated ordering of such acts or events are not to beinterpreted in a limiting sense. For example, some acts may occur indifferent orders and/or concurrently with other acts or events apartfrom those illustrated and/or described herein. Further, not allillustrated acts may be required to implement one or more aspects orembodiments of the description herein, and one or more of the actsdepicted herein may be carried out in one or more separate acts and/orphases.

Thus, as can be appreciated from above, the present disclosure providesa cup wash disk for cleaning a photoresist process tool. An upper plateis arranged over a lower plate to define a cavity between the upper andlower plates. The lower plate comprises peripheral openings in fluidcommunication with the cavity and arranged along a periphery of thelower plate. A plurality of shims is arranged between the upper andlower plates to space the upper and lower plates and to define slitsbetween the upper and lower plates. The slits are in fluid communicationwith the cavity.

In other embodiments, the present disclosure provides a method forcleaning a photoresist process tool. A cup wash disk is placed in achamber of a photoresist process tool. The cup wash disk comprises shimsarranged between an upper plate and a lower plate to define a pluralityof slits between the upper and lower plates. The cup wash disk isrotated while spraying solvent into a cavity of the cup wash disk frombelow the cup wash disk. The cavity is defined between the upper andlower plates and is in fluid communication with the slits. The solventmoves through the cavity to the slits to spray the solvent out the slitstowards sidewalls of the chamber.

In yet other embodiments, the present disclosure provides a photoresistprocess tool. A workpiece support is arranged in a chamber. A cup washdisk is arranged on the workpiece support. The cup wash disk comprisesan upper plate and a lower plate stacked upon one another and spaced bya plurality of shims arranged between the upper and lower plates. Theshims are laterally spaced along a periphery of the cup wash disk.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A photoresist process tool comprising: aworkpiece support arranged in a chamber; and a cup wash disk (CWD) onthe workpiece support and comprising an upper plate, a lower plate, anda plurality of shims, wherein the upper plate overlies the lower plateand is separated from the lower plate by a cavity and the shims, whereinthe shims are spaced along a periphery of the CWD to define a pluralityof slits in fluid communication with the cavity, and wherein the cavityhas a first height and a second height respectively at the shims and acenter of the CWD, and wherein the second height is non-zero and lessthan the first height.
 2. The photoresist process tool according toclaim 1, wherein the first and second heights extend from a lowersurface of the upper plate respectively to a first upper surface of thelower plate and a second upper surface of the lower plate, and whereinthe first and second upper surfaces are at different elevations abovethe workpiece support.
 3. The photoresist process tool according toclaim 1, wherein the upper plate completely covers the cavity.
 4. Thephotoresist process tool according to claim 1, wherein the first heightis adjacent to the shims and extends along sidewalls of the shims,wherein the cavity has a third height directly under the shims, andwherein the third height is different than and between the first andsecond heights.
 5. The photoresist process tool according to claim 1,wherein the plurality of shims comprises a first shim and a second shimrespectively on opposite sides of the cavity, and wherein a lowersurface of the upper plate extends continuously from the first shim tothe second shim while crossing the center of the CWD.
 6. The photoresistprocess tool according to claim 1, wherein the CWD is symmetrical abouta vertical axis at the center of the CWD.
 7. The photoresist processtool according to claim 1, wherein the lower plate defines a back-rinseopening leading into the cavity, and wherein the photoresist processtool further comprises: a back-rinse nozzle underlying the CWD andconfigured to spray solvent into the cavity through the back-rinseopening.
 8. A photoresist process tool comprising: a workpiece supportarranged in a chamber; and a cup wash disk (CWD) on the workpiecesupport and comprising a first plate, a second plate, and a plurality ofspacer structures, wherein the first and second plates are verticallystacked and separated from each other by a cavity and the spacerstructures, wherein the spacer structures are spaced along a peripheryof the CWD, wherein the spacer structures individually wrap around acorner of the first plate from a surface of the first plate facing thesecond plate to a sidewall of the first plate, and wherein the spacerstructures individually extend along the sidewall of the first platefrom a top of the first plate to a bottom of the first plate.
 9. Thephotoresist process tool according to claim 8, wherein the spacerstructures have L-shaped profiles.
 10. The photoresist process toolaccording to claim 8, wherein the CWD further comprises a ring-shapedstructure vertically stacked with the first and second plates, andwherein the spacer structures extend along the sidewall of the firstplate from the ring-shaped structure to the corner of the first plate.11. The photoresist process tool according to claim 10, wherein thering-shaped structure and the spacer structures are integrated together.12. The photoresist process tool according to claim 10, wherein thefirst and second plates are circular and have individual diameters lessthan that of the ring-shaped structure.
 13. The photoresist process toolaccording to claim 8, wherein the spacer structures define a pluralityof slits spaced along the periphery of CWD and in fluid communicationwith the cavity, wherein the CWD has a back-rinse opening leading intothe cavity and configured to receive a solvent while spun by theworkpiece support, and wherein the CWD is configured to expel thesolvent through the slits while spun by the workpiece support.
 14. Thephotoresist process tool according to claim 8, wherein the CWD furthercomprises a spacer-support structure vertically stacked with the firstand second plates, wherein the spacer structures extend along thesidewall of the first plate from the spacer-support structure to thecorner of the first plate, and wherein the spacer-support structure ison an opposite side of the first plate as the surface of the firstplate.
 15. A photoresist process tool comprising: a workpiece supportarranged in a chamber; and a cup wash disk (CWD) on the workpiecesupport and comprising an upper plate, a lower plate, and a plurality ofshims, wherein the upper plate overlies the lower plate and is separatedfrom the lower plate by a cavity and the shims, wherein the shims arespaced along a peripheral sidewall of the CWD to define a plurality ofslits in fluid communication with the cavity, and wherein the shimsoverhang the cavity; wherein the plurality of shims comprises a firstshim, wherein the first shim and the lower plate have a first verticalseparation offset from the slits and in the cavity, wherein the upperplate and the lower plate have a second vertical separation at a centerof the CWD and in the cavity, and wherein the second vertical separationis a non-zero value less than the first vertical separation.
 16. Thephotoresist process tool according to claim 15, wherein the lower platehas a first sidewall and a second sidewall respectively facing thecavity and facing away from the cavity, wherein a separation between thefirst and second sidewalls is less than a width of the shims.
 17. Thephotoresist process tool according to claim 15, wherein the shims andthe upper plate define a top surface of the cavity, and wherein the topsurface of the cavity has a stepped profile at the shims.
 18. Thephotoresist process tool according to claim 15, wherein the upper plate,the lower plate, and the first shim define a common sidewall that isstraight from top to bottom.
 19. The photoresist process tool accordingto claim 15, wherein top surfaces respectively of the shims directlycontact a bottom surface of the upper plate, and wherein bottom surfacesrespectively of the shims directly contact a top surface of the lowerplate.
 20. The photoresist process tool according to claim 15, whereinthe upper plate completely covers the cavity.